Electromagnetic waves have been used in various applications to supply energy to objects. In the case of radio frequency (RF) radiation for example, electromagnetic energy may be supplied using a magnetron, which is typically tuned to a single frequency for supplying electromagnetic energy only in that frequency. One example of a commonly used device for supplying RF energy is a microwave oven. Typical microwave ovens supply electromagnetic energy at or about a single frequency of 2.45 GHz.